Hinge mechanism for foldable electronic device

ABSTRACT

A hinge mechanism ( 500 ) includes a shaft ( 1 ), a cam ( 2 ), a housing ( 3 ), a cam follower ( 4 ), and an elastic member ( 5 ). The shaft has a pair of shaft ends. The cam has a cam tip. The housing has an open end and a hole defined at an opposite end. The cam follower has a cam surface configured to engage with the cam tip. The cam, the cam follower and the elastic member surround the shaft in turn. The cam follower and the elastic member are received in the housing, while the cam is partly received in the housing. The cam is rotatable relative to the shaft and non-rotatable relative to the housing, and the cam follower is slidable and non-rotatable relative to the shaft. The hinge mechanism is easily assembled, and modularized for convenient installation into a main housing and a cover of a foldable electronic device.

FIELD OF THE INVENTION

The present invention generally relates to hinge mechanisms, and more particularly to a hinge mechanism for hinging together housings of a foldable, portable electronic device such as a mobile phone or a PDA (Personal Digital Assistant).

BACKGROUND

Portable mobile phones generally have two housings rotatably joined by a type of hinge that allows the housings to fold upon one another. Many such foldable mobile phones have most of the electronics in one housing, called the main housing, and fewer electronics in the other housing, called the cover. Other such foldable mobile phones have all the electronics in the main housing, with the cover serving only to cover a keypad and a display of the main housing. The main housing and the cover are connected together by a hinge mechanism. Generally, the opening or closing of most covers is achieved by means of cams and a spring of the hinge mechanism.

FIG. 1 illustrates a hinge assembly used in a foldable mobile phone 100. The foldable mobile phone 100 includes a main housing 102 and a cover 104. The hinge assembly includes two cams 200, 202, a spring 204, and a pair of posts 106 contained in the main housing 102. A channel 1042 is defined through an end of the cover 104. The cam 202, the spring 204, and the cam 200 are fixed in the channel 1042 in that order. The cams 200, 202 protrude out from the channel 1042 and engage with the posts 106. When the cover 104 is rotated, the cams 200, 202 rotate along with the cover 104, and stop the cover 104 in a position where it maintains an angle of 180° relative to the main housing 102.

However, the hinge assembly includes a variety of individual pieces that must be installed within the foldable mobile phone when the foldable mobile phone is assembled. This does not meet the growing trend for foldable mobile phone manufacturers to use integrated one-piece hinge assemblies that can be quickly and easily press-fitted into foldable mobile phone sub-assemblies during manufacturing. Manufacturing costs associated with non-integrated hinge assemblies are higher than those associated with one-piece hinge assemblies.

What is needed, therefore, is a hinge mechanism which is modularized, easy to be installed into foldable mobile phones, and low in cost.

SUMMARY

A hinge mechanism for a foldable, portable electronic device includes a shaft, a cam, a housing, a cam follower, and an elastic member. The shaft has a pair of shaft ends. The cam has a cam tip. The housing has opposite housing ends, with one housing end being an open housing end. The housing has a housing hole defined at the opposite housing end. The cam follower has a cam surface arranged to engage with the cam tip. The cam, the cam follower, and the elastic member surround the shaft in turn. The cam follower and the elastic member are received in the housing, while the cam is partly received in the housing. The cam is rotatable relative to the shaft and non-rotatable relative to the housing, and the cam follower is slidable and non-rotatable relative to the shaft.

A foldable electronic device has a main housing, a cover, and a hinge mechanism for hinging the main housing and the cover. The hinge mechanism includes a shaft, a cam, a housing, a cam follower, and an elastic member. The shaft has a pair of shaft ends. The cam has a cam tip. The housing has opposite housing ends, with one housing end being an open housing end. The housing has a housing hole defined at the opposite housing end. The cam follower has a cam surface arranged to engage with the cam tip. The cam, the cam follower, and the elastic member surround the shaft in turn. The cam follower and the elastic member are received in the housing, while the cam is partly received in the housing. The cam is rotatable relative to the shaft and non-rotatable relative to the housing, and the cam follower is slidable and non-rotatable relative to the shaft.

The hinge mechanism is simple, easily manufactured, and relatively inexpensive. In addition, the hinge mechanism is modularized, so it is easily installed into the main housing and cover of a foldable mobile phone or other electronic device.

Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, isometric view of a foldable mobile phone with a hinge of the related art;

FIG. 2 is an exploded, isometric view of a hinge mechanism in accordance with a preferred embodiment of the present invention;

FIG. 3 is an assembled view of the hinge mechanism of FIG. 2, but viewed from another aspect;

FIG. 4 is a cross-sectional view of FIG. 3 taken along line III-III thereof, showing a closed state of the hinge mechanism;

FIG. 5 is similar to FIG. 4, but showing another state of the hinge mechanism; and

FIG. 6 is an isometric view of an electronic device having the hinge mechanism of FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 2-6, a hinge mechanism 500 of the present invention is used in foldable mobile phones, PDAs (Personal Digital Assistants), and so on. Hereinafter, the hinge mechanism 500 applied to foldable mobile phones will be described. An exemplary foldable mobile phone includes a first part like a main housing 300 and a second part like a cover 400.

The hinge mechanism 500 includes a shaft 1, a cam 2, a housing 3, a cam follower 4, a spring 5, an arresting member 6, and a pin 7.

The shaft 1 is column-shaped, and has a first shaft end 10 and an opposite second shaft end 11. The first shaft end 10 has a flange 12 thereon. A flattened shaft portion 14 is formed from the opposite second shaft end 11 through a central section of the shaft 1. A transverse hole 16, whose axis is vertical to an axis of the shaft 1, is defined in the shaft 1 proximate the second shaft end 11 and within the flattened shaft portion 14.

The cam 2 is column-shaped and a cam hole 20 runs through the cam 2 along an axis of the cam 2. A diameter of the cam hole 20 is smaller than that of the flange 12 of the shaft 1. A pair of tips 22 are symmetrically formed on an end of the cam 2. A fixing hole 24, coaxial to the cam hole 20, is defined in the cam 2 on the opposite end. A diameter of the fixing hole 24 is larger than that of the cam hole 20.

The housing 3 is substantially a flattened cylinder, and has a first housing end 30 and an opposite second housing end 31. The housing 3 is open at the first housing end 30, and a polygonal hole 32 is defined at the opposite second housing end 31. The opening at the first housing end 30 and the polygonal hole 32 at the second housing end 31 communicate with each other through a central hole (not labeled) of the housing 3. The tips 22 are received in the polygonal hole 32. The rest of the cam 2 protrudes beyond the housing 3. The outside wall of the housing 3 forms a fixing surface 34, to engage with the cover 400 of the foldable mobile phone.

The cam follower 4, received in the housing 3, is column-shaped. The cam follower 4 has a first follower end 40 and an opposite second follower end 41. A through hole 42 is defined in the cam follower 4 along an axis thereof. The shape of the through hole 42 is same as the cross-section of the flattened shaft portion 14. The through hole 42 has a diameter small enough to stop the cam follower 4 rotating relative to the flattened shaft portion 14, but large enough to allow the cam follower 4 to slide along the flattened shaft portion 14. A pair of valleys 44 are defined on the first follower end 40. A pair of peaks 45 are formed on the second follower end 41 symmetrically to the valleys 44. The valleys 44 and the peaks 45 form a cam surface 48. A counteractive portion 46 is formed on the second follower end 41. A diameter of the second follower end 41 is less than that of the first follower end 40.

The spring 5, which is received in the housing 3 and surrounds the shaft 1, is column-shaped. One end of the spring 5 is coiled around the counteractive portion 46, and the opposite end of the spring 5 stands against the arresting member 6.

The arresting member 6, which is engaged in the main housing 300 of the foldable mobile phone, is a polygonal prism. A hole 62 is defined in the arresting member 6 along an axis thereof. The shape of the hole 62 is same as the cross-section of the flattened shaft portion 14. The hole 62 has a diameter small enough to stop rotational action between the arresting member 6 and the flattened shaft portion 14. A pinhole 64 is defined in the arresting member 6 perpendicular to the hole 62, to receive the pin 7.

In assembly, firstly, the flattened shaft portion 14 of the shaft 1 runs through the cam 2, the housing 3, the cam follower 4, the spring 5, and the arresting member 6. The flange 12 of the shaft 1 is contained in the fixing hole 24. The tips 22 of the cam 2 are inserted into the polygonal hole 32 so as to form a cam surface together with an inner face of the housing 3 inside the housing 3. The cam follower 4 and the spring 5 are received in the housing 3. The flattened shaft portion 14 non-rotatably engages in the through hole 42 of the cam follower 4 and the hole 62. The spring 5 biases the cam follower 4 and the cam 2 into engagement. The valleys 44 of the cam follower 4 match with the tips 22 of the cam 2. The pin 7 is fixed into the pinhole 64 and the transverse hole 16, so that the hinge mechanism is assembled to a unified whole, as shown in FIG. 3.

Finally, referring to FIG. 6, the hinge mechanism 500 is installed in joints of the foldable mobile phone. The housing 3 matches with the cover 400, and the arresting member 6 matches with the main housing 300. When the cover 400 is closed onto the main housing 300, the two tips 22 lie in the two valleys 44 of the cam follower 4, as shown in FIG. 4.

When the cover 400 is manually rotated up toward an open position, the housing 3 and the cam 2 rotate together with the cover 400. Because the shaft 1 and the arresting member 6 are fixed to the main housing 300, and because the cam follower 4 is non-rotatable and slidable relative to the shaft 1, the cam follower 4 rotates relative to the cam 2. The tips 22 of the cam 2 slide out of the valleys 44 of the cam follower 4, and the cam 2 forces the cam follower 4 to move toward the arresting member 6, simultaneously compressing the spring 5. When the tips 22 reach the peaks 45 of the cam follower 4, as shown in FIG. 5, the spring 5 is compressed to its shortest length. Once the tips 22 have passed over the peaks 45, the manual rotation of the cover 400 is stopped. The spring 5 decompresses and forces the cam follower 4 to push the cam 2 to rotate until the tips 22 of the cam 2 return into the valleys 44 of the cam follower 4. Thus, the cover 400 continues to rotate relative to the main housing 300 until the cam 2 stops rotating. At such point, the cover 400 is in the open position. Alternatively, the cover 400 can be opened to a prearranged angle, as limited by one or more corresponding structures provided on the main housing 300 or/and the cover 400. The process of closing the cover 400 is substantially the reverse of the above-described opening process.

In alternative embodiment, the spring 5 can be instead by other elastic member such as a rubber element.

It is believed that the embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. 

1. A hinge mechanism for a foldable electronic device, comprising: a shaft having a pair of shaft ends; a cam having a cam tip; a housing having opposite housing ends, one housing end being an open housing end, the housing further having a housing hole defined at the opposite housing end; a cam follower having a cam surface arranged to contact the cam tip; and an elastic member; wherein the cam, the cam follower, and the elastic member surround the shaft in turn, the cam follower and the elastic member being received in the housing, the cam being partly received in the housing, the cam being rotatable relative to the shaft and non-rotatable relative to the housing, and the cam follower being slidable and non-rotatable relative to the shaft.
 2. The hinge mechanism as claimed in claim 1, wherein a flange is formed at one shaft end of the shaft to stop the cam from falling off, and an arresting member is formed at another shaft end of the shaft to stop the elastic member falling off.
 3. The hinge mechanism as claimed in claim 1, wherein the shaft comprises a flattened shaft portion.
 4. The hinge mechanism as claimed in claim 1, wherein the cam tip of the cam is received in the housing hole of the housing.
 5. The hinge mechanism as claimed in claim 1, wherein the housing is substantially a flattened cylinder, and the housing hole of the housing is polygonal.
 6. The hinge mechanism as claimed in claim 3, wherein the cam and the cam follower are substantially cylindrical, and the flattened shaft portion runs through the cam and the cam follower.
 7. The hinge mechanism as claimed in claim 3, wherein the cam defines a through hole along an axis thereof, and the shape of the through hole is same as a cross-section of the flattened shaft portion of the shaft.
 8. The hinge mechanism as claimed in claim 1, wherein the elastic member is a spring, which is column-shaped.
 9. A foldable electronic device, comprising: a main housing; a cover; and a hinge mechanism comprising a shaft having a pair of shaft ends, a cam having a cam tip, a housing having opposite housing ends, one housing end being an open housing end, the housing further having a housing hole defined at the opposite housing end, a cam follower having a cam surface arranged to contact the cam tip, and an elastic member; wherein the hinge mechanism hinges the main housing and the cover, the cam, the cam follower, and the elastic member surround the shaft in turn, the cam follower and the elastic member being received in the housing, the cam being partly received in the housing, the cam being rotatable relative to the shaft and is non-rotatable relative to the housing, and the cam follower being slidable and non-rotatable relative to the shaft.
 10. The hinge mechanism as claimed in claim 9, wherein a flange is formed at one shaft end of the shaft, to stop the cam from falling off.
 11. The hinge mechanism as claimed in claim 9, wherein an arresting member, which is formed at another shaft end of the shaft, to stop the elastic member falling off, is engaged with one of the main housing and the cover.
 12. The hinge mechanism as claimed in claim 9, wherein the shaft comprises a flattened shaft portion.
 13. The hinge mechanism as claimed in claim 9, wherein the cam tip of the cam is received in the housing hole of the housing.
 14. The hinge mechanism as claimed in claim 11, wherein the housing, which is substantially a flattened cylinder, is engaged with another of the main housing and the cover.
 15. The hinge mechanism as claimed in claim 14, wherein the housing hole of the housing is polygonal.
 16. The hinge mechanism as claimed in claim 12, wherein the cam and the cam follower are substantially cylindrical, and the flattened shaft portion runs through the cam, the cam follower.
 17. The hinge mechanism as claimed in claim 12, wherein the cam defines a through hole along an axis thereof, and the shape of the through hole is same as a cross-section of the flattened shaft portion of the shaft.
 18. The hinge mechanism as claimed in claim 9, wherein the cam surface comprises a peak and a valley.
 19. The hinge mechanism as claimed in claim 9, wherein the elastic member is a spring, which is column-shaped.
 20. An electronic device comprising: a first part of said electronic device defining a side to be exposable; a second part of said electronic device separably attachable to said first part and movable relative to said first part between a first position thereof where said second part abuts against and covers said side of said first part, and a second position thereof where said second part moves away from said side to expose said side; and a hinge mechanism disposed between said first and second parts and used to contribute to movement of said second part relative to said first part between said first and second positions of said second part, said hinge mechanism comprising a housing attachably movable along with one of said first and second parts and a shaft attachably movable along with another of said first and second parts, a cam of said hinge mechanism separably and partially extendable into said housing so as to form a cam surface in said housing in cooperation with an inner face of said housing, and said cam surface engagable with a cam follower from said shaft so as to controllably guide said movement of said second part between said first and second positions of said second part. 